Rubbing machine



Dec. 28, 1954 D. DlCKlNsON 2,697,897

RUBBING MACHINE Filed Jan. 12, 1950 5 Sheets-Sheet 3 United States Patent O RUBBING MACHINE Donald I. Dickinson, Menominee, Mich., assigner to Peninsula Tool Company, Inc., Menominee, Mich., a corporation of Michigan Application January 12, 1950, Serial No. 138,157

16 Claims. (Cl. 51-170) This invention relates to rubbing machines and is more particularly concerned with improvements in small power machines of this character which are useful for sanding, buing, polishing or otherwise finishing a surface.

It is a general object of the invention to provide a relatively small, portable, power driven rubbing machine which is simple in construction, which is highly eicient in operation and which may be economically manufactured.

It is a more specific object of the invention to provide an improved power driven rubbing machine which is characterized by a vibrating rubbing pad or shoe wherein the rubbing shoe is caused to vibrate with an irregular motion.

It is a further object of the invention to provide a rubbing machine comprising a relatively fixed housing and a vibrating pad which is connected by a ilexible element with an eccentric mounted in the housing and wherein the eccentric is driven by power means also mounted in the housing.

It is a still more specific object of the invention to provide a rubbing machine comprising a downwardly opening housing, a rubbing pad connected to the bottom of the housing by flexible means permitting a vibratory motion of the pad, a power driven shaft depending from the housing, a rotatable member having an eccentric portion mounted in the housing and driven by the power shaft and a flexible connection between the eccentric portion and the rubbing pad whereby rotation of the power shaft imparts an irregular vibratory motion to the pad. It is another object of the invention to provide a rubbing machine comprising in combination a relatively n fixed downwardly opening housing, a rubbing pad adjacentthe bottom of the housing, flexible means for connecting the pad with a power driven eccentric member in the housing and a plurality of elements for connecting the pad to the housing which permit an irregular vibray l tory .motion of the pad in all directions relative to the housing.

It is still another object of the invention to provide in a rubbing machine of the type described a plurality of relatively flexible connecting elements arranged about@ the periphery of the rubbing shoe and securing the same in spaced relation to the bottom of the support or housing for the power driven shaft, the exible connecting elements being adapted to permit limited vibratory motion of the rubbing shoe relative to the support in` any-.1:

direction.

It s a further object of the invention to provide in a rubbing machine of the type described a plurality of spaced resilient posts for connecting the rubbing shoe to the housing or other support for the driving means.

It is another object of the invention to provide a rubbing machine comprising a relatively fixed supporting frame member, a rubbing pad, resilient members connecting the pad in spaced relation to the frame member,

the eccentric with the eccentric engaging the same approximately on the center of the pad.

These and other objects of the invention will be apparent from a consideration of the physical embodiments `a driven shaft mounted in the frame with the end thereof thereof which are shown by way of illustration in the accompanying drawings, wherein:

ice

Fig. 1 is a side elevation of a power driven rubbing machine embodying the principles of the invention, the lower portion thereof being broken away to show the mechanism in longitudinal section;

Fig. 2 is a section taken generally on the line 2-2 of Fig. 1;

Fig. 3 is a transverse section taken generally on lines 33 of Fig. l;

Fig. 4 is a partial longitudinal section showing a modified form of the invention;

Fig. 5 is a section taken generally on the lines 5 5 of Fig. 4;

Fig. 6 is a section taken generally on the lines 6--6 of Fig. 4;

Fig. 7 is a partial longitudinal section showing a still further modification of the invention;

Fig. 8 is a detail section showing a modified form of connection member for securing the rubbing shoe to the supporting frame; and

Fig. 9 is a detailed section similar to Fig. 8 showing a further modified form of connecting member.

Referring to Figs. 1 to 3 of the drawings, there is illustrated a motor driven mechanism which embodies the principal features of the invention. The details of the motor are not illustrated and are immaterial to the invention, it being understood that an electric motor, an air motor or any other type of power means may be employed for providing the operating force in the machine.

The machine illustrated comprises a relatively fixed frame consisting of a motor housing 10 and a downwardly opening pad or shoe supporting frame or casing member 11, the motor housing 10 being detachably secured by screws 12 or other fastening elements to the forward top portion of the member 11.

The motor 13 is mounted in the housing member 10 and provided with a power shaft 14 which depends therefrom and extends downwardly into the casing 11 being supported in a pocket or recess 15 therein by means of a bearing member 16. A fan 17 is secured on the power shaft 14 above the casing member 11 and provides for the circulation of air through the slots at 18 adjacent the upper end of the housing 10.

The housing 10 is provided with a laterally or rearwardly extending handle formation 19 which provides a means for the operator to grasp the machine in one hand. The handle 19 accommodates the electrical cord indicated at 20 and a current controlling switch mechanism indicated at 21 for supplying power to the electric motor 13. In the case of an air driven motor the handle 19 will, of course, accommodate a suitable air conduit and controlling valve.

A rubbing pad or shoe 22 supports the rubbing element 23, which may be an abrasive coated sheet, as illustrated, or any other element suitable for engaging the work surface to be treated. The rubbing shoe 22 comprises a plate member 24 having downwardly extending peripheral flange 25 and a pad-like member 26 of rubben or similar resilient material. The member 26 is of sufcient depth to extend beyond the anges 25 and accommodate on its lower face the abrasive coated member 23 or other work performing element. The rubbing shoe 22 is connected in spaced relation to the downw wardly opening casing member 11 by means of a plurality of circumferentially spaced resilient connecting elements or posts 27. The posts 27 each comprise a cylindrical section of resilient material, such as rubber, having a metal block 28 vulcanized or otherwise secured in its opposite ends with the outer end ush with the end of the post. The posts 27 are secured at the upper end to the lower face ofthe inside of the casing member 11 by means of screws 29 secured in threaded engagement with the metal blocks 28. At their lower ends they are secured to the upper face of the plate member 24 of the shoe 22 by means of screws 30 in the same manner. The posts 27 provide a resilient connection between the shoe 22 and the casing member 11 which 'permits limited movement of the shoe relative to the casing in all directions while at the same time providing resistance to such movement in any direction.

The lower end of the power driven shaft 14 is provided Fgetragen? with a pulley 31 which is secured thereon by a set screw 32. The pulley 31 `i`s eorinected in vdriving 'relation by a belt 33 with an eccentric pulley 34. The eccentric 34 is .provided with a bearing receiving recess in its upper face which 'receivesa bearing 35`secur'edfon a stub shaft 36. The shaft 36 depends from the upper rear wall porvtion -37 1of the casing member 1-1 and -is secured thereto by the screw 3S. The lpulley 34 -is provided with Va dependirig'eccentric shaft portion 39 which projects into a pocket or recess 40 in a connecting yoke member 41 Vand `is secured therein by afbearing 42 which is tted over the eccentric 39 and into the pocket 40.

The connecting 'yoke 41E-isof relatively rigid material and generally Y-shaped. Itis arranged -in parallel relation-tothe rubbing shoeff22-and Ais secured thereto at three points by resilient blocks 43. Each of the blocks 43 is formed of rubber or Vsimilar resilient material and provided with a metal anchor plate 44 in its upper face and asimilar anchor Vplate 45 in its lower face. The anchor' plates 44 and 45 are Avulcanized vor otherwis'eps'ecurely fastened tothe blocks v'43. The blocks 43 are secured at the ends of the legs of the member 41 and to the plate member 24 by screws 46 and 47 in threaded engagement in the apertures in lthe anchor plates 44 and 45. Blocks 43 resiliently connect the yoke member 41 in spaced relation to the rubbing shoe -22 with the center of the pocket 40 and the bearing 42connecting the same to the eccentric portion 39oflthepulley34 located farther toward the rear end of the-lmachine'than the front end of the same.

The rubbing shoe 22 is preferably provided at its ends with clamping means for securingin position thereon the abrasive coated member 23. The illustrated securing means comprises a rubber covered roller 48 arranged adjacenteach end `of theplate 24. The rollers 48 are each mounted on a shaft '48 'and 'held in yposition by a pair of spring members 49 which are secured adjacent the sides of the plate member 24 by rivets or other securing means 49 at one end thereof. Atthe other end'the spring mem*Y bers 49 are each provided with a curved retaining portion 49"'accomm0dating the projecting end of the'shaft 48 of theroller48. One outer end of each roller shaft 48 may be conveniently formed with a slot 48 for receiving a screw driver to-.perrnit the clamping rollers'48 to be ro tated'in frictional engagement with the 'turned over ends of the abrasivernemberh23 tosecure thesarne in clamping relation on the top of'the'plate'Z-i. The shaft end may be recessed or provided with any suitablefend formation to accommodateany other form of'turning tool.

ln operation the power ldriven Yshaft 14 rotates the pulley 34 by means offthe'belt33 which imparts an eccentric rnovement to the'bearing 42 andthe member 41 by reason ofthe connection with'the eccentric'portion 39. The'rnovement of the member 41 is transmitted through the resilient.connectingrpads 43tothe shoe 22 which carries the abrasiveor rubbing member 23. Due'to the resiliency of the connecting blocks 43 themovement of the shoe'2-2is irregularand varies with thepressure applied againstthe workand'other factors, such as-the nature of the rubbing surface and thenature of the materialbeing worked, which effect resistance to the motion-of the member41. Portions of the rubbing pad or shoe may vibrate in a longitudinal direction while other portions may simultaneously vibrate -ina transversedirection or diagonally relative to the supporting casing 11. The vertical thrust caused by engaging theshoer22 with the work is absorbed by the resilient connectingposts `27 and the'resilient connecting pads43 rwithout Idamage to the vibrating mechanism connecting the member 41 with the power shaft 14.

lReferring to Figs. 4 to 6, there is illustrated a modified form of themachine which comprises the downwardly opening supporting Yframe or casing member 50 and a plurality of resilient depending connecting posts 51 which support thereon a work element carrying pad or shoe 52. The shoe 52 is adapted to vibrate a'gainst'the'resistance of the connecting elements or posts S1 in any direction relative tothe supporting casing 50. A motor housing 53 in which the motor 54 is supported is arranged above the casing member 50 with the motor shaft 55 depending therefrom and extending into the casing member S in thc same manner as in thefpreviously described form.

A pulley 56 is secured onthe end of the shaft 55 and connected by a driving belt57 with an eccentricl pulley 58 which is supported on the-depending stub shaft 59. Down- Wardly extending eccentricporton 60 on the eccentric pulley 58 projects intoasocket formation 61 in the connecting rod member 62 and is secured in rotatable relation therein by the bearing formation 63. The pocket 61 is provided at one end of the connecting member 62, the other end of the connecting member 62 being vulcanized or otherwise secured in a resilient connecting block 64 which is provided on its lower face with a metal attaching plate 65 integrally secured thereto and fastened by means of screws 66 to the upper surface of the plate 67 which forms the upper portion of the rubbing shoe 52.

In operating this form of the machine the power shaft 55 rotates the eccentric pulley 58 by means of the pulley 56 on t'ne shaft 55 and the connecting drive belt 57. Eccentric motion is transmitted from the pulley 5S to the connecting rod 62 by means of the eccentric portion 60 on the former which is rotatably connected with the end of the rod 62. Circular motion imparted to the free end of the rod 62 is transmitted through the block 64 to the rubbing shoe 52 against the resistance offered by the rcsilient posts 51 which connect the shoe 52 with the rela tively fixed casing member 50. The resulting vibratory Vmotion of the shoe 52 is irregular due to the resiliency of the connecting posts 51 and the connecting block 64. The motion of the shoe 52 at any particular time is influenced by the operative conditions previously described.

A further modified form of the rubbing machineis illustrated in Fig. 7. ln this formof the device a downwardly' opening supporting casing 70 is connected by resilient posts 71 with a rubbing shoe 72. A power driven shaft 73 is arranged to extend Yinto the casing 70 and is connected by means of a pulley 74, secured on the end of the shaft 73, and a driving belt I75, with an eccentric pulley 76 which is supported on a depending stub-shaft 77. The shaft 77 is positioned in relatively close relation to vthe pulley 74. An eccentric portion 78 on the pulley v76 extends into a recess or pocket 79 -in a connecting plate member 80 and is rotatably secured therein by the bearing formation S1. The connecting plate 80 may be 'r-lshaped and attached at fourpoints to the rubbing shoe 72 by resilient connecting blocks 82. The recess or pocket formation 79 in the connecting platerd is located approximately in the geometrical center of the rubbing shoe 72 so that the center of movement ofthe latter coincides approximately with the center of rotation of the eccentric 76. The resulting vibratory motion in this form of the machine is variable in extent as well as -in Ypattern because of the resiliency and location of the connecting posts 71 and the connecting blocks 82 and is determined by the operating conditions asipreviouslydescribed. The location of the connecting bearing for the eccentric in the geometrical center of the shoe is not restricted to this form of connecting bar orplate member. -This principle for locatingthe bearing may be embodied `in the other forms of the mechanism which are illustrated and described herewith. v

In Figs. 8 and 9 there are illustrated alternative constructions forthe connecting elements which `secure .the rubbing shoe to the supporting casing. AReferring rst to Fig. 8, the connecting element comprises a lengthof "esilient tubing 91, such as rubber or the likephaving se cured, by vulcanizing or other means, tapped metal blocks 92 and 93 in its opposite ends. At one-end the connecting element'90 is secured to the upper wall '94 of the supporting casing 95 by means of a screw'96. At the other end the element 90 is rsecured to lthefplate member 970i the rubbing shoe'98 by means of a screw 99. 'Resilient wire clamping rings'100 may be employed to insure that the tapped elements 92 and "93 will remain in position in the ends of thetube section 91. The resilient tubing 91 permitsmovement of the shoes 9S in any direction relative'to the casing'95 while at the same time offering resistance to such movement.

In Fig. 9 a' connecting element 101.is'illustrated which comprises a section of' coiled spring *102 and' cap members 103 at opposite ends thereof to which the spring- 102 is secured by welding or the like las .indicated at `104. Each cap 103 isprovided with a threaded center aperture 105 for receiving a securing screw. 'At one en'd the cap 103 is secured by screw`106 to the upper `wall of the casing 107 and at the other end the screw 108 attaches the end of the element to the plate 109 of'the rubbing shoe 110. A plurality ofthe elements 101 are arranged around the periphery of the shoe 110 and permit limited movement of the same in any direction relative tothe casing 107.

While specific details 'of constructionand.specific materials have been referred to"indeseribingtheillustrated aeavgasov formsl of ythe invention, it will be understood that other details of construction and other materials may be resorted to within the spirit of the invention.

I claim: 1

1. lIn a rubbing machine, a downwardly opening rigid housing, a rubbing pad, flexible means depending within said housing and connecting said pad in spaced relation below said housing, said exible means permitting a vibratory motion of said pad in any direction relative to said housing, a power driven shaft mounted in said housing and extending downwardly therein, an eccentric rotatably mounted in said housing, means connecting said eccentric and said shaft in driving relation, a generally Y- shaped bar member spaced above said pad, a bearing supported in said bar member intermediate the ends thereof and connecting said eccentric therewith, and ilexible blocks connecting the ends of said bar member with said pad whereby when said power shaft is rotated an irregular vibratory motion will be imparted to said pad.

2. In a rubbing machine, the combination of a rigid support, a power shaft extending downwardly through said support, a driven member rotatably mounted on said support in spaced relation to said power shaft and connected in driving relation therewith, said driven member having a portion eccentric to its axis of rotation, a rubbing pad, flexible means connecting said rubbing pad to said support, an elongate bearing receiving member having end portions spaced above ,said rubbing pad, means independent of the means connecting the pad to the support for flexibly connecting the end portions of said bearing receiving member to said pad, a bearing positioned intermediate the ends of said bearing receiving member andconnecting said eccentric portion on said power driven member thereto, whereby rotation of said power driven member causes said pad to vibrate relative to said support with a non-uniform motion.

3. In a rubbing machine, a supporting frame, apower driven shaft mounted in said frame, a rubbing pad, a plurality of resilient members connecting said pad to said frame in spaced relation to the end of said shaft, said resilient members being arranged in spaced relation around the margins of said pad, said resilient members connecting said pad to said frame for relative movement in all directions, a rigid Y-shaped arm, a flexible connection between the end of each leg of said Y-shaped arm and said pad, and means including an eccentric connecting said arm at a point intermediate the ends thereof in driving relation with the end of said shaft, the point of connection of said means with said arm being approximately in the geometric center of said pad, whereby upon rotation of said shaft said pad will be vibrated relative to said frame with an irregular motion.

4. In a rubbing machine, a relatively rigid supporting ing housing, a rubbing shoe, means connecting said shoe in spaced relationto said housing, said connecting means being flexible and permitting a limited vibratory motion of said shoe relative to said housing in any direction, a power shaft mounted in said housing and extending toward said shoe, an eccentric rotatably mounted in said housing, means connecting said eccentric and said power shaft in driving relation, a rigid member connected to said eccentric and movable relative to said housing upon rotation of said eccentric, and a flexible member spaced from said eccentric connecting sai rigid member to said shoe independently of the means connecting the shoe to the housing, said exible member permitting limited vibratory motion of said shoe relative to said rigid member in all directions whereby when said power shaft is rotated an irregular vibratory motion will be imparted to said shoe.

5. In a rubbing machine, the combination of a rigid support, a power driven member rotatably mounted on said support and having a portion eccentric to its axis of rotation, a rubbing shoe having a relatively rigid backing plate, a plurality of spaced flexible posts connecting said backing plate directly to said support for relative movement in any direction, a rigid Y-shaped bearing receiving member, a bearing positioned in said Y-shaped bearing receiving member and connecting said eccentric portion on said power driven member thereto and flexible connecting means between each leg of said Y-shaped bearing receiving member and the backing plate of said shoe, said flexible connecting means being independent of said flexible posts and permitting limited movement in any direction between said Y-shaped bearing receiving member and said shoe upon movement of said bearing receiving member lby rotation of said power driven member, whereby rotation of said power driven member will cause said shoe to vibrate relative to said support with an irregular motion.

In a rubbing machine, a supporting casing having a driven shaft mounted therein, a rubbing shoe having a relatively rigid backing member, means for connecting said casing and said rigid backing member, said shoe being positioned in spaced relation beyond the end of said shaft, said connecting means comprising a plurality of flexible post-like elements independently connected at opposite ends to said casing and said rigid backing member, said flexible elements being arranged in spaced relation around said shaft and adjacent the periphery of said shoe, said liexible elements permitting limited movement of said backing member relative to said casing in all directions and means independent of the casing and of said flexible elements connecting said rigid backing member and the end of said shaft, said last mentioned connecting means comprising au eccentric rotatably mounted in said casing, means connecting said eccentric and said shaft in driving relation, a rigid bar member spaced above said backing member, a bearing supported in said bar member and connecting the eccentric therewith and spaced exible blocks connecting said bar member with said backing member at points spaced from said bearing whereby when said shaft is rotated an irregular vibrating motion will be imparted to said rubbing shoe.

7. A rubbing machine as recited in claim 6 wherein said flexible elements comprise coil spring members.

8. A rubbing machine as recited in claim 6 wherein said iiexible elements comprise hollow exible tubular sections having rigid connecting members at opposite ends for securing said elements to said casing and said pad, respectively.

9. A rubbing machine as recited in claim 6 wherein said flexible elements comprise solid rubber blocks having rlgrd connecting members at opposite ends for securing said elements to said casing and pad, respectively.

l0. In a rubbing machine, a supporting frame, a power driven shaft mounted in said frame, a rubbing pad, a plurality of relatively exible members connecting said pad to said frame adjacent the end of said shaft, said ilexible members being arranged in spaced relation around the margin of said pad whereby said pad is connected to said frame for movement relative thereto in any direction, a rigid elongate arm, means including an eccentric connecting one end of said arm in driving relation with the end of said shaft and flexible means adjacent the other end of said arm connecting said arm with said pad independently of said flexible members whereby upon rotation of said shaft said pad is vibrated with an irregular motion.

ll. In a rubbing machine, a supporting frame, a power driven shaft mounted in said frame, a rubbing pad having a relatively rigid backing member, a plurality of resilient post members connecting said backing member to said frame adjacent said shaft, said resilient post members being arranged in spaced relation adjacent the margin of said backing member and providing for movement of said backing member relative to said frame in any direction, an elongate rigid arm member, exible means connecting opposite ends of said arm member to said backing member, said flexible means being independent of said resilient post members and providing for movement of said backing member relative to said arm member in any direction, and means including an eccentric connecting said arm member intermediate its ends in driving relation with said shaft, the connection of said last mentioned means with said arm member providing for eccentric movement of said arm member upon rotation of said shaft.

l2. In a rubbing machine, a downwardly opening rigid housing, a rubbing pad having a relatively rigid backing member, exible means extending within said housing and connecting said backing member in spaced relation to said housing, said flexible means permitting a vibratory motion of said pad in any direction relative to said housing, a power driven shaft mounted in said housing and extending downwardly therein, an eccentric rotatably mounted in said housing, means connecting said eccentric and said shaft in driving relation, a rigid yoke member extending longitudinally in spaced relation above 'said backing member, .fa `bearing supported :said -yoke member adjacent fone end :thereof `-and connecting fsaid eccentric therewith, and laterally spaced flexible tblocks adjacent "the other fend `'of said yoke member Sand com necting said yoke member to said rigid backing member independently of fthe means connecting lsaid ba'cking member to said fhousi'ng whereby when -said power :shaft is rotated an irregular nvibratory .motion vrwill `be imparted to isaid Zp'ad.

13. .11n a rubbing machine, a frelatively Vrigid supporting housing, 'a lrubbing lshoe having `a relatively rigid back-ing member., means vconnecting .said Ebacking member -in spaced .relation "to said housing, said 'connecting .means being .flexible and permitting a tlirnited vibratory V-motion of said 'shoe relative Ito said housing fin vany direction, la power Sshaftt `mounted :in Avsaid .housing 'and extending ttoward said shoe, la rigid plate-like connecting member posiitioned 'between said :housing land said Vsh'oe in spaced relation '.t'o said 'backing member, means .including Van :eccentr-i'c "connecting one faceofsaid 'rigid connecting member in driving relation with the end of Vsaid vpower shaft and exible .means 'connect-ing Athe opposite face of said rigid connecting fmember'with Vsaid backing member independently 'of ithe :means connecting said backing -rnember to said housing whereby up'onirotation of said'shaftlan irreg- 'ular motion 'will be imparted to 'said shoe.

114. .1I-nia rubbing machineas recited inlclaim .13,"wherein saidmeans con'necting said backingmembe'r Ito said housing :consists Yof a plurality fofpost-like .members yof resilient material which are each connected at the opposite ends .thereof to the housing and the .backing member, lrespectively, and whichlarespacedaround `said power shaft and adjacent ihefperipheryfof said backinglmember.

215. In a rubbing machine, a relatively -rigid supporting housing, a rubbing shoe, a plurality of `post members f ing tsaidlecce'ntric and 'Said power shaft in driving =relation, a rigid member connected Ito :said eccentric `and movable nelat'ive =to 'said lhousing upon ,rotation of lsaid eccentric, and a sexible member Aspaced from .said eccen tric connecting said rigid member to said shoe, which flexible member is lindependent 'of :the post members connecting the shoe .to :the housing, said leXible member permitting limited vibratory `motion of said shoe relative to said rligid member in .all directions whereby when said power shaft is rotated an irregular vibratory motion will be imparted to said shoe.

=16. In `a `rubbing ytool, a relatively rigid supporting housing, a rubbing shoe, ymeans connecting said shoe to said housing for vibratory movement of said shoe `in a plane which is spaced :in predetermined relation to said housing, said lconnecting 'means :comprising a plurality of .peripherally spaced cylindrical post members, which post members are lformed rof relatively flexible material and which lare 'secured fat their opposite :ends -to 'said housing vand shoe, respectively, said -post members permitting limited vibratory :motion 'of ysaid shoe relative to said housing in :any ldirection in said plane, a power shaft mounted in said lhousing and extending toward said shoe, an .eccentric rotatably mounted in said housing, mcans'cofnnecting'said eccentric and said :power shaft in 'driving relation, la rigid member connected l'to said eccentric and movable 1relative -to said :housing .upon -rotation of said eccentric -and means connecting Asaid rigid members to said shoe whereby when lsaid power shaft is rotated a Ivibrator-y :motion will rbe imparted to said shoe.

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